The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels o ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Latidae of

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Perciformes. It is widespread throughout much of the

Afrotropical realm The Afrotropical realm is one of Earth's eight biogeographic realms. It includes Africa south of the Sahara Desert, the majority of the Arabian Peninsula, the island of Madagascar, southern Iran and extreme southwestern Pakistan, and the island ...

, being native to the Congo,

Nile The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

Niger ) , official_languages = , languages_type = National languagesLake Chad Lake Chad (french: Lac Tchad) is a historically large, shallow, endorheic lake in Central Africa, which has varied in size over the centuries. According to the ''Global Resource Information Database'' of the United Nations Environment Programme ...

, Volta,

Lake Turkana Lake Turkana (), formerly known as Lake Rudolf, is a lake in the Kenyan Rift Valley, in northern Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake. B ...

, and other river basins. It also occurs in the

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

waters of Lake Maryut in

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

. The Nile perch is a fish of substantial economic and food-security importance in East Africa. Originally described as ''Labrus niloticus,'' among the

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

wrasse The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes. They are typically small, most of them le ...

s, the species has also been referred to as ''Centropomus niloticus''. Common names include African snook, Victoria perch (a misleading trade name, as the species is not native to

Lake Victoria Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropical lake, and the world's second-largest fresh water lake by surface area after ...

, though they have been introduced there), and many local names in various African languages, such as the Luo name ''mbuta'' or ''mputa''. In

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

, it is called ''sangara'', ''sankara'', or ''chenku''. In Francophone African countries, it is known as ''capitaine''. Its name in the

Hausa language Hausa (; /; Ajami: ) is a Chadic language spoken by the Hausa people in the northern half of Nigeria, Ghana, Cameroon, Benin and Togo, and the southern half of Niger, Chad and Sudan, with significant minorities in Ivory Coast. Hausa is a mem ...

is ''giwan ruwa'', meaning "water elephant".

Description

''L. niloticus'' is silver in color with a blue tinge. It has distinctive dark-black eyes, with a bright-yellow outer ring. One of the largest

es, it reaches a maximum length of nearly , weighing up to . Mature fish typically range from , although many fish are caught before they can grow this large. Capitaine Nile Perch

Adult Nile perch occupy all habitats of a lake with sufficient

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

concentrations, while juveniles are restricted to shallow or nearshore environments. A fierce

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill t ...

that dominates its surroundings, the Nile perch feeds on fish (including its own species),

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean g ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is est ...

s, and

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

s; the juveniles also feed on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

. Nile perch use schooling as a mechanism to protect themselves from other predators.

Invasive species

Nile perch have been introduced to many other lakes in Africa, including Lake Victoria and the artificial

Lake Nasser Lake Nasser ( ar, بحيرة ناصر ', ) is a vast reservoir in Southern Egypt and northern Sudan. It is one of the largest man-made lakes in the world. Before construction, Sudan was against the building of Lake Nasser because it would encr ...

. The

World Conservation Union The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natur ...

's Invasive Species Specialist Group considers ''L. niloticus'' one of the world's 100 worst invasive species. The state of

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

in Australia levies heavy fines on anyone found in possession of a living Nile perch, since it competes directly with the native barramundi, which is similar and grows to long, while the Nile perch grows to long. The species is of great commercial importance as a food fish. The Nile perch is also popular with sport anglers, as it attacks artificial fishing lures, and it is also raised in

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

Lake Victoria introduction

The introduction of this species to Lake Victoria is one of the most cited examples of the negative effects alien species can have on ecosystems. The Nile perch was introduced to Lake Victoria in East Africa in the 1950s, and has since been fished commercially. In 2003, Nile perch sales to the EU reached 169 million euros. Sport-fishing in the region of Uganda and Tanzania provided additional income from tourism. Its introduction was ecologically disruptive and is attributed with causing the extinction or near-

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the Endling, last individual of the species, although the Functional ext ...

of several hundred native species, with some populations fluctuating with

commercial fishing Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must oft ...

and the actual Nile perch stocks. The Nile perch initially fed on native cichlids, but with decreasing availability of this prey, it now consumes mainly small

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are ref ...

and

minnow Minnow is the common name for a number of species of small freshwater fish, belonging to several genera of the families Cyprinidae and Leuciscidae. They are also known in Ireland as pinkeens. Smaller fish in the subfamily Leusciscidae are c ...

s. The alteration of the native ecosystem had disruptive socioeconomic effects on local communities bordering the lake. Many local people have been displaced from their traditional occupations in the fishing trade and brought them into the cash economy, or before the establishment of export-oriented fisheries, turned them into economic refugees. At least initially, nets strong enough to hold adult Nile perch could not be manufactured locally and had to be imported for a high price. The introduction of Nile perch has also had additional ecological effects on shore. Native cichlids were traditionally sun-dried, but because Nile perch have a high fat content (higher than cichlids), they need to be smoked to avoid spoiling. This has led to an increased demand for firewood in a region already hard-hit by

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...

soil erosion Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, a ...

, and

desertification Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly arid. It is the spread of arid areas caused ...

. The

Academy Award The Academy Awards, better known as the Oscars, are awards for artistic and technical merit for the American and international film industry. The awards are regarded by many as the most prestigious, significant awards in the entertainment ind ...

-nominated documentary '' Darwin's Nightmare'' by Hubert Sauper (a French-Austrian-Belgian production, 2004) deals with the damage that has been caused by Nile perch introduction, including the import of weapons and ammunition in cargo planes from Europe, which are then used to export Nile perch, further exacerbating conflict and misery in the surrounding regions. Regardless of whether it is considered positive or negative, the trophic web of Lake Victoria appears to have been drastically impoverished by the introduction of this novel near-

top-level predator An apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic le ...

. While the ecosystem seems to be moving towards a new equilibrium, neither its former state nor the state of fisheries on Lake Victoria can ever easily be brought back.

Fishing

On Lake Victoria, the only (small) trawlers present belong to research institutes. Small-scale fishing boats are propelled mostly by sails, and paddles are used on the smallest boats. However, the number of boats propelled by outboard engines is on the rise, denoting a greater capital intensity of the local Nile perch fishery. One to three fishermen use a boat. The fish are caught mainly with gill nets and hand lines and sometimes (short) long lines. Those caught by gill nets are usually dead when the nets are lifted. The fish are kept in the boat without protection or ice and taken to landing sites, mostly beaches, where they are weighed and purchased by company buyers using insulated boats or vans with ice, or the fish are bought by local women. The fishery also generates indirect employment for additional fish processors, transporters, factory employees, and others. All along the lakeshore, 'boom towns' have developed in response to the demands of fishing crews with money to spend from a day's fishing. These towns resemble shanties, and have little in the way of services. Of the 1,433 landing sites identified in the 2004 frame survey, just 20% had communal lavatory facilities, 4% were served by electricity, and 6% were served by a potable water supply.

Threats

Despite being a successful invasive species, the fish faces threats. Being a species of

megafauna In terrestrial zoology, the megafauna (from Greek μέγας ''megas'' "large" and New Latin ''fauna'' "animal life") comprises the large or giant animals of an area, habitat, or geological period, extinct and/or extant. The most common thresho ...

, the most obvious threats to the species are overfishing and the use of

illegal fishing Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries. Illegal fishing takes p ...

gear, as well as invasive

water hyacinths ''Pontederia crassipes'' (formerly ''Eichhornia crassipes''), commonly known as common water hyacinth is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range.European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are located primarily in Europe, Europe. The union has a total area of ...

Notes

References

External links

* * * Lipton, David.

. ''Animal Diversity Web.'' Ann Arbor: University of Michigan Museum of Zoology, 2003. * Snoeks, Jos.
Ecology of ''Lates niloticus''
. ''Global Invasive Species Database.'' Updated 22 September 2004. *

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

.
Alien Species Invade the Planet
. Press release, 11 May 2001.
Species Profile - Nile Perch (''Lates niloticus'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located ...

. {{Taxonbar, from=Q654130 Nile perch Afrotropical realm fauna Freshwater fish of West Africa Fish of Chad Fish of Egypt Freshwater fish of Kenya Fish of Sudan Fish of the Democratic Republic of the Congo Fish of the Republic of the Congo Freshwater fish of Tanzania Freshwater fish of Uganda Fish of Lake Turkana Congo River Nile Nile basin Nile perch Taxa named by Carl Linnaeus